(1) Field of the Invention
The present invention relates to a nozzle that introduces gas into a container for purging the inside of the container, and particularly relates to a nozzle that introduces gas without contacting the container.
(2) Description of the Related Art
In the manufacture of semiconductor devices such as LSI, wafers, glass substrates, reticles and the like, the devices need to be stored such that they are not deteriorated or degenerated. For example, the wafers need to be stored in a low oxygen atmosphere to prevent oxidization, and the reticles need to be stored in an atmosphere where moisture (H2O) is removed in order to suppress the growth of haze. Further, it is necessary to avoid the particles (fine dust) from adhering to the wafers and others as much as possible. For this reason, in many cases, the wafers are stored in a container filled with a clean gas composed of a type of gas suitable for the stored object.
However, as disclosed in Japanese Unexamined Patent Application Publication No. 2001-31212, there are cases where it is necessary to sort the stored wafers into multiple containers. In such a case, it is necessary to open the containers. Thus, a process known as “purging” is performed in order to maintain the high degree of cleanliness of the container by introducing clean gas into the open container to keep the pressure in the container more positive than the atmosphere outside of the container.
Furthermore, it has been considered that storing the reticles and others in a container where the purging is constantly performed causes less contamination of the reticles and others than storage in a sealed container, since the reticles and others are stored for a relatively long period of time. Accordingly, there are purge apparatuses which can constantly purge the container with clean gas.
However, it is known that the stored wafers and reticles are contaminated with particles on rare occasions, even when a conventional purge apparatus is used. After devoted research and diligent effort, the inventors of the present invention have reached the finding that the rare contaminations with the particles are caused by the purge apparatus. Furthermore, the inventors also discovered that, since the container placed in the purge apparatus and the nozzle, which discharges the gas into the container, contact each other, the friction and impact between the container and the nozzle form particles; and the particles subsequently contaminate the inside of the container.